1. Technical Field
The present invention relates to a thermally augmented oxygenation system for wound care and method, and more particularly, but not by way of limitation, to a programmable system adapted for oxygenation of a wound area in conjunction with high thermal contrast modalities, specifically adapted to facilitate the healing process.
2. Description of the Related Art
An important aspect of planned patient treatment is wound care. Medical facilities are constantly in need of advanced technology for the cleaning and treatment of skin wounds. The larger the skin wound, the more serious the issues are of wound closure and infection prevention. The rapidity of the migration over the wound of epithelial and subcutaneous tissue adjacent the wound is thus critical. Devices have been developed and/or technically described which address certain aspects of such wound healing. For example, U.S. Pat. No. 6,695,823 B1 describes a wound therapy device that facilitates wound closure. A vacuum pump is taught for collecting fluids from the wound. WO 93/09727 discloses a solution for wound drainage by utilizing negative pressure over the wound to promote the above references migration of epithelial and subcutaneous tissue over the wound.
Another aspect of wound care is the use of oxygen. The use of oxygen for the treatment of skin wounds has been determined to be very beneficial in certain medical instances. The advantages are multitudinous and include rapidity in healing. For this reason, systems have been designed for supplying high concentration of oxygen to wound sites to facilitate the healing process. For example, U.S. Pat. No. 5,578,022 teaches an oxygen producing bandage and method. One of the benefits cited in U.S. Pat. No. 5,578,022 is the ability to modulate a supply of concentrated hyperbaric oxygen to skin wounds. Although oxygen is beneficial in direct application of predetermined dosages to skin wounds, too much oxygen can be problematic. Oxygen applied to a wound site can induce the growth of blood vessels for stimulating the growth of new skin. Too much oxygen, however, can lead to toxic effects and the cessation of healing of the wound. It would be an advantage, therefore, to maximize the effectiveness of oxygen applied to a wound area by enhancing the absorption rate of oxygen into the skin and tissue fluids. By enhancing the absorption rate of the oxygen in the wound, less exposure time and concomitantly fewer toxic side effects to the endothelial cells surrounding the wound, such as devasculation, occurs. It would be a further advantage, therefore, to utilize existing medical treatment modalities directed toward other aspects of patient therapy to augment oxygenation for wound care.
It has been accepted for many years by medical care providers that patient thermal therapy can be very advantageous for certain injuries and/or post operative recovery. For this reason, thermal therapy has been advanced and many reliable and efficient systems exist today which provide localized thermal therapy to patients in both pre and post surgical environments.
Addressing first thermal therapy systems, several devices have been engineered to deliver temperature controlled fluids through pads or convective thermal blankets to achieve the above purpose. Typically, these devices have a heating or a cooling element, a source for the fluid, a pump for forcing the fluid through the pad or blanket, and a thermal interface between the patient and the temperature controlled fluid. U.S. Pat. No. 4,884,304 to Elkins is, for example, directed to a mattress cover device which contains liquid flow channels which provide the selective heating or cooling by conduction.
Devices have also been developed for simply providing heat or cooling to a person in bed. Electric blankets containing electric heating elements have been used, for example, to provide heat to people in bed. Likewise, cooling blankets, such as the blanket disclosed in U.S. Pat. No. 4,660,388 to Greene, have also been proposed. Greene discloses a cooling cover having an inflatable pad with plenum chambers at opposite ends thereof. Cool air is generated in a separate unit and directed to the pad and out to a number of apertures on the underside of the pad and against the body of the person using the cover.
A disposable heating or cooling blanket is disclosed in U.S. Pat. No. 5,125,238 to Ragan et al., which has three layers of flexible sheeting. Two of the layers form an air chamber while a third layer includes a comfortable layer for contact with the patient. Conditioned air is directed toward the covered person through a multiplicity of orifices in the bottom layers of the blanket.
A temperature controlled blanket and bedding assembly is also disclosed in U.S. Pat. No. 5,989,285 to DeVilbiss et al., assigned to the assignee of the present invention. The disclosure of DeVilbiss discloses a temperature controlled blanket and temperature control bedding system having the provision of both recirculating temperature controlled fluid and temperature controlled gas to enhance performance for convectively heating or cooling a patient. Counter-flow or co-flow heat exchanging principles between the temperature controlled liquid and the temperature controlled gas achieve temperature uniformity across different sections of the blanket and the bedding system. Drapes and the temperature controlled bedding system provided temperature controlled envelope around a person using the bedding system. In one embodiment of the bedding system, the air portion of the bedding system is provided for use with a patient that supplies the fluid portion of the overall bedding system. In another embodiment of the bedding system, the fluid portion of the bedding system is provided for use with a patient bed which supplies the air portion of the overall bedding system.
U.S. Pat. No. 5,097,829 to Quisenberry describes an improved temperature controlled fluid circulating system for automatically cooling a temperature controlled fluid in a thermal blanket with a thermoelectric cooling device having a cold side and a hot side when powered by electricity. The temperature controlled fluid is cooled by the cold side of the cooling device and pumped through, to, and from the blanket through first and second conduits.
Finally, co-pending U.S. patent application Ser. No. 10/894,369 teaches a sequential compression blanket for use with heating or cooling therapy. In this particular embodiment, the utilization of thermal therapy with sequential compression in a programmable format which further has the option of the introduction of oxygenation through a perforated membrane disposed between the patient and the thermal therapy pad is taught. These advances in the medical industry have been recognized as advantageous to both the medical care providers as well as the patients. The precise manner of oxygenation application is, however, still in need of improvement.
The present invention provides improvements in wound care by providing multiple wound healing approaches such as negative pressure over the wound as well as oxygenation in conjunction with thermal therapy. By combining an oxygenation modality that is utilized in conjunction with thermal therapy and/or sequential compression in association therewith, the benefits of both negative wound pressure and oxygenation treatments can be enhanced.